The utilization of waste heat has become an increasely important consideration in times where conservation of energy, especially fossil fuel energy, becomes increasely scarce and/or high priced.
In addition, present day communication and scientific satellites use conduction or radiation into space for rejecting waste heat. With increasing mission requirements and associated higher heat loads, a more efficient heat rejection system is needed. Heat pipes and pumped loops are sufficiently developed to meet increased heat load requirements; however, both of these systems have limitations. Heat pipes have a limited heat transport capacity, especially for very large radiators or in spinning satellites. Pumped loops are not limited by the size of the radiator network, but they do consume a considerable amount of power, and some components such as pumps and valves have limited reliability. Thus, there is a need for combining the versatility of pumped loops with the reliability and efficiency of a heat pipe.